The social network has been trialling a sophisticated system which makes it much easier for customers to focus their advertising spend on ads that are relevant to users, rather than taking a scattergun approach and hoping the right people will look at them. The platform launched in the US and Europe on Thursday.

The move is expected to boost Facebook, whose share price has almost halved since its troubled $104m flotation in May amid concerns that it is not able to make enough money from advertising.

Rather than reserving a fixed slot, the new real-time bidding platform, Facebook Exchange, allows companies to specify who they want to reach in a more calculated way.

It enables them to enter an ongoing, automatic auction for advertising space, and bid to place their adverts, depending on who is looking at Facebook at that particular time.

Advertisers are also able to set limits on what they want to spend, ensuring even small businesses can enter the race for advertising slots. Google uses a similar system to power its very successful Google AdWords service.